Plug



June 21', 1938. N. CHlRi-:LSTEIN 2,121,338

PLUG

` INVENTOR June 2l, 1938.

N. CHIRELSTEIN PLUG Filed oet'. 1o, 1935 2 Sheets-Sheet 2 Patentes June 21, 193s.

oFFicE.

PLUG I Nathan esigente-1n, Newark, N. J. Application Octoberlo, 1935, Serial No. 44,378

1 claim (cl. us5-61) My invention relatesto electric plugs such as described in the patent issued to me bearing date.

of April 14th, 1936, and numbered 2,037,562.

The object of my inventionis to provide an 'improved attachment plug embodying` means for holding the contact members of the male and -female portions of the plug in rm contact over a considerable surface to eiect perfect transmission of an electric current therethru.

A further object is to providel a male portion having blades or legs of less thickness than those of the standard type now in general use, to render them more resilient so that they will bend -without breaking either the legs or the plastic material base to which they are attached. and also to permit them to bend easily in opposite directions from the median `line thru the recesses of the female member, to` effect contact over-a considerable surface with the socket conductors,

regardless of which side of the recesses they may be located in.

A further object` is to .provide a plugin which the contact members will be held together under constant spring pressure over a considerable area to eilect a frictional engagement therebetween regardless of -which side of the recesses the contacts may be located in the female member;

Referringto the drawings which form a part yci this specification:

Fig. 1 is a vertical .partial sectional view` of the plug, in which the male and female portions are united in current conduction relation.

Fig. 2 is a view oi' the inner end of the male portion,taken online 2--2 of Fig. 1.

, Fig. 3 is a perspective view of one form of leg construction in which a branch portion is pressed from the body or stem portion ofthe leg to its offset position by a stamping operation.

Fig. 4 is an illustrative vview showing the leg' as it/-appears when in contact with the conducting strip located on the inner side ofthe recess of the female member.

Fig. 5 is aview, partly in section, of the male l 5g inner side .of the face of afelmale member which is also illustrated in Figure 9, many of which have heretofore been in general use.

Fig. 8 is a view of the underside of the plug cap shown in Figure?. f Fig. 9 is a vertical partial sectional view in '5 which the leg members are shown, each of which comprises a stem and branch portion, the branches oi which are located on the outer sides of the stems insteadv of on the inner sides thereof as 'show n in Figure 7. 10

Fig. l0 is a perspective view of a single leg formed with the branch carried on the outer side of the stem portion. Fig. 1l is a perspective view showing; the branch carried on the inner side of the stem por- 15 tion.

Fig. 12l is a perspective view of a leg with the branch carried on the inner side thereof and curved outwardly therefrom instead of being formed with a-straight plane surface, as shown 20 in Figures 10 and l1.

ill indicates the female or socket portion ofv .the plug which is of astandard type, some of indicates the face of the body portion of Ithe male 30 member.

Fig. 4 shows a socket portion o f a plug in which the contact members i3 are located adjacent theinner sides of the recesses.

Il indicates the body portion of the malelme/m- 35 ber, which may be made of hard plastic or soft rubber in the usual manner.

I5 indicates the male contact members, hJerein after referred to as the blades orlegs.

The legs are fastened to the body portibn by 4Q screws It which extend thru the plate portion I'l in the usual way, or they maybe attached in any other. satisfactory manner.

'Ihe legs'normally extend straight from the body portion parallel with'each other, and enter 45 the socket recesses midway between-the walls thereof. an'd the branch portions I9' extend. from the free endsoi'r the stems to the face of the body portion.

'I'he consti-notion shown in Figures -1, 3 and 4. 5u

is cheaper to make than that shown in Figures and e. as less metaliareqwred the branch portionsconsisting of tongues struck from the blades sf intermediate the edges thereof.

This construction also vis 'slightly more resilient 55 so that when used with socket contacts located adjacent the inner walls as shown in Figure 4; a longer surface will'contact the socket terminal and also the pressure between them will be in- 'cr-eased.

When the legs are used in a socket having its terminals located adjacent the inner walls, as shown in Figure 4, the stem portions bend or flex the greater distance; whereas when used as shown in Figure l, the branch portion is bent more than the stem portion.

`Referring now to Figures 5 and 6, the branch portion is provided by bending the stem at 2| into the position and shape shown, and some metal is punched out to provide`the slots 22.

These slots weaken the stem and branch p0rtions at these points, thus making vthem more flexible, and. causes a sharper bending of the branch at 23, providing a shoulder similar to that shown in Figure 3, to be formed automatically when the leg is forced into the socket, and serving the same purpose.

The drawings illustrate the plug on a scale twice the size of the actuaLconstruction.

The metal stem and 'its branch are` of equal thickness, about one-thirty second of an inc h, and this reduction in -thickness relative to onesixteenth'of an inch as now-generally used in standard plugs of this type, provides a plug hav. ing very flexible and resilient legs which accommodate themselves to socket constructions in which the walls of the recesses and the terminals are badly worn, making good contact with said terminals regardless of which side of the recesses they may be located adjacent to.

In .both embodimentsr of the invention` the branch portions are free ended and project from near the entering ends of the blades and extend toward the body portion a distance at least equal to the contacting length of the blades so that the free ends will not operate to lock or prevent uncoupling the plug by simple withdrawal.

,Whencoupled each blade Aand its respective branch portion is wedged toward each other against the receptacle contacts, thereby obtainins spring` pressedeontachand good mechanical connection.

' A considerable number of the, yPlugs haveJ beenmade and used'successfully with both types of socketmemberaand thebodyportions of the/ therefore will not become locked in flxed relation with the female member.

In passing the legs into position in a female coupling portion of a plug having shulders I0' and Il' formed therein as illustrated. the shoulders 2l of each of the branches II are at first forced ltoward their stems and after they have passed beyond theshoulders I0' the inclined surfaces in abutment with said shoulders III' or I I' as the case may be, due to their spring action, serve to automatically draw the male member into close unionwith the female member and serves to hold them in removable locked engagel nient, as will be readily understood. f l

It will be observed that the free ends of the branches extend to a point closely adjacent the face of the plug so that they cannot snap under the shoulders formed in the female member, and also that the stems contact with the blades of the female portion perfectly due to the resilient action coupled with the flexibility of the co-acting terminals.

eIaving thus described my invention I claim as n An attachment plug comprising a body portion of insulating material having' a pair of flat contact blades extending therefrom. said blades being formed of resilient conducting material and spaced apart a distance corresponding to the separation between the socket openings of 'a standard receptacle, said blades each having a free ended branch struck therefrom intermediate the side and end edges thereof with the branch of each blade extending from its point of connection with the blade adjacent the`free end of the latter to a point adjacent to the face of the body portion of the plug, said branch being abruptly offset at its point of connection with the blade to provide a shoulder, the portion of the branch between said shoulder and its free end being ilat and offset from said blade, the oonstruction being such that each resilient blade'` and its resilient branch will be wedged. toward each other in the act of coupling the plug with a standard receptacle.

- NATHAN CHIRELBI'EIN. 

